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PubMed1998

Coronary vasculopathy in polycythemia vera.

Thrombosis is a common complication in polycythemia often causing death. In coronary artery occlusion, thrombosis due to hyperviscosity and thrombocytosis is mostly discussed as the origin of the infarction. We discuss the case of a 30-year-old male patient, with polycythemia, who died of myocardial infarction. On autopsy the vessels showed neither ateriosclerotic changes nor thrombotic occlusions. Instead, a marked intima proliferation was found leading to multiple occlusions whereas media and adventitia were unchanged. This pattern of a coronary vasculopathy has not been described before, and can be interpreted as an alternative mechanism for vascular occlusion in polycythemia. Similar histopathological changes have already been found in skin lesions in erythromelalgia, a common symptom in polycythemia.

Adult↗
PubMed2002

What is the standard treatment in essential thrombocythemia.

The treatment of patients with essential thrombocythemia (ET) should be based primarily on the expected risk of major thrombotic complications. Although the specific values chosen for separating different risk categories are in part arbitrary, the following recomendations can be made. Young asymptomatic subjects with platelet counts below 1,500x10(9)/L are at lower risk and can be followed untreated. However, it should be emphasized that thrombotic events can also occur in a small percentage of these lower-risk cases. Low-dose aspirin (100-300 mg/day) should be given to patients with symptoms of microvascular occlusion, such as erythromelalgia or transient neurological attacks, and avoided in those with bleeding manifestations. The risk/benefit of low-dose aspirin in the primary prevention of thrombosis in asymptomatic patients remains uncertain. For high-risk patients (age >60 years, or platelet count >1,500x10(9)/L, or previous thrombosis), hydroxyurea, plus aspirin in the case of thrombosis, is the treatment of choice because its efficacy in preventing thrombotic complications has been proven in a randomized clinical trial. However, the possible long-term leukemogenicity of this drug, as well as that of other effective cytoreductive agents such as busulphan and pipobroman, remains a major concern. Anagrelide and interferon could overcome this worry but their efficacy has been hitherto demonstrated only in lowering the platelet count. Controlled clinical studies showing a benefit in preventing thrombotic and hemorrhagic complications are urgently needed.

Antineoplastic Agents↗
PubMed2006

[Raynaud phenomenon in dermatology. Part 1: Pathophysiology and diagnostic approach].

Raynaud phenomenon (RP) is characterized by recurrent spasms of small digital arterioles/arteries at fingers and toes, usually triggered by cold and emotional stress. Clinically a sudden pallor of individual digits is followed by reactive hyperemia, in severe cases also by cyanosis. One distinguishes between primary RP, i.e. RP without an underlying disease or drug intake, and secondary RP, which is causally related to an underlying disease or to intake of certain drugs (e.g. interferon, cisplatin). Primary RP is frequent (prevalence of about 13-20% in northern or central Europe), while secondary RP is rare, but the major presenting symptom for systemic sclerosis (SSc). Differential diagnosis includes cold-induced pallor, acute embolic events, paroxysmal hematoma of the finger or erythromelalgia. Vasoconstrictive mechanisms outweigh vasodilatory ones in endothelial cells and vascular smooth muscle. Although soluble mediators such as endothelin or certain prostaglandins have been exploited successfully for therapy, the extent of their involvement in the initial pathophysiology of RP is unclear. Secondary RP (associated with SSc) additionally features morphological alterations with compromise of the vessel lumen. As RP can result in severe discomfort and complications, timely diagnosis and treatment is essential.

Humans↗
PubMed1995

[Drug-induced iatrogenic arterial diseases].

Several drugs have been shown to cause vasomotor troubles such as Raynaud's phenomenon, erythromelalgia, vasculitis, livedo reticularis, or acrocyanosis. Vascular symptoms may develop a few weeks or more after drug initiation, particularly when other drugs are associated than can potentiate vascular side effects. In this review, the authors described the main characteristics of drug-induced vasculopathy, particularly those associated with ergotamine derivates, beta blocking agents or antineoplastic chemotherapy.

Arteries↗
PubMed1995

[Arterial hypertension due to mercury poisoning: diagnostic value of captopril].

BACKGROUND: Mercury poisoning is a rare cause of hypertension in children. Urinary excretion sometimes remains low despite severe clinical intoxication. CASE REPORT: A 32 month-old girl was admitted with hypertension, tachycardia, apathy, irritability and excessive sweating. Erythromelalgia and neurologic symptoms permitted the diagnosis of acrodynia. Urine mercury remained normal until chelation. Captopril significantly increased urine mercury concentration but failed to improve clinical manifestations. Clinical improvement required infusions of BAL for 5 days then oral dimercaptosuccinic acid for 3 months. Metal vapors originated from the mercury which spilled from a broken thermometer onto the carpet. COMMENTS: Low basal urine mercury could be associated with real mercury poisoning. Small amounts of metal mercury held in a thermometer could produce a high level of mercury vapor leading to intoxication in young children. The binding capacity of metal ions by captopril could be used to increase urine mercury output. Nevertheless, captopril therapy fails to improve acrodynia. Total elimination of mercury requires long-term therapy with BAL or dimercaptosuccinic acid. CONCLUSIONS: An unexpected mode of intoxication and low basal urine mercury are not decisive arguments against mercury poisoning, which is the only cause of acrodynia.

Administration, Oral↗
PubMed2004

[Raynaud's phenomenon in children].

Raynaud's phenomenon has been described more than 140 years ago, its prevalence in the general population is high, and yet the underlying pathological mechanisms are only partly understood. In children, female preponderance has been reported, as it is also the case in adults, and the disease usually starts after the age of 10. Diagnosis and differential diagnosis, in particular with erythromelalgia, are usually made through patient's or parent's interrogatory. It is important to distinguish primary Raynaud's phenomenon, which is usually benign, from Raynaud's phenomenon secondary to connective tissue disease. To this regard, nailfold capillaroscopy is of great help, as may be more recently introduced techniques such as thermography and digital blood pressure response to cooling. Primary Raynaud's phenomenon usually only requires simple physical measures (avoidance of exposure to coldness, gloves in winter, ...) plus sometimes oral calcium blockers. By contrast, Raynaud's phenomenon secondary to connective tissue disease requires systemic investigations, assessment and treatment of the underlying disease and, in some cases, more aggressive treatments such as intravenous carboprostacyclin (Iloprost).

Age of Onset↗
PubMed2006

Raynaud's phenomenon.

Vascular acrosyndromes constitute a common reason for physician visits. They are associated with connective tissue disease; for example, 90% of patients with scleroderma experience Raynaud's phenomenon. The rheumatologist must strive to establish the diagnosis, to identify a potential underlying cause, and to prescribe effective treatment when the symptoms are incapacitating. Raynaud's phenomenon is the acrosyndrome most commonly encountered by rheumatologists. The diagnosis of Raynaud's phenomenon rests on clinical grounds. Nailfold capillaroscopy and immunological tests are useful chiefly for determining the cause. Calcium-channel antagonists are the treatment of reference for Raynaud's phenomenon. Drugs introduced over the last few years for severe refractory forms include prostacyclin and its derivatives, endothelin receptor antagonists, and phosphodiesterase inhibitors. These drugs were developed as a result of new knowledge on the pathogenesis of Raynaud's phenomenon. Acrocyanosis, which is extremely common, and erythromelalgia are the other main vascular acrosyndromes.

Adrenergic alpha-Antagonists↗
PubMed1991

Essential thrombocythemia in young adults.

Essential thrombocythemia is typically a disorder of adults in the sixth or seventh decade of life and is characterized by frequent thrombohemorrhagic complications. In young patients, the optimal management of complications is controversial. We studied 56 young adults (33 female and 23 male patients) with a diagnosis of essential thrombocythemia. The mean duration of follow-up was 4.68 years. The mean platelet count at diagnosis was 1,328,000/mm3. Platelet aggregation studies in 21 patients demonstrated hypoaggregation to epinephrine; spontaneous platelet aggregation was present in 4. At diagnosis, 39 patients were asymptomatic, and thrombocytosis was discovered incidentally. Throughout follow-up (up to 20 years), 24 patients remained asymptomatic. Thrombotic complications developed in 24 patients; they were life-threatening in only 3. The most common vaso-occlusive symptoms were migraine headache (in 12 patients) and erythromelalgia (in 3). Minor hemorrhagic complications occurred in six patients, and none was life-threatening. Serious complications (one cerebral and two myocardial infarctions) occurred in three patients, all of whom recovered. Two deaths occurred, neither of which was attributable to essential thrombocythemia. The treatment regimens used were chemotherapy in 9 patients, antiaggregating agents in 7, radioactive phosphorus in 1, the newer platelet-lowering agent anagrelide in 10, and only observation in 29. No treatment-related acute leukemias developed. This series of young patients with essential thrombocythemia, the largest to date, demonstrates a low incidence of life-threatening complications and a favorable long-term prognosis. Therapeutic recommendations should remain conservative, and potential leukemogens should be avoided unless serious complications develop. Anagrelide may be useful in young patients with thrombocythemia who are symptomatic.

Adolescent↗
PubMed1978

Long-term treatment of parkinsonism with bromocriptine.

92 patients with parkinsonism have been treated with bromocriptine for up to 30 months. 48 continue to receive bromocriptine with benefit; of these, 35 take bromocriptine (mean dose 53 mg daily) in combination with levodopa and 13 take bromocriptine (mean dose 45 mg daily) without levodopa. In those who were originally on levodopa, addition of bromocriptine allowed a mean 41% reduction in the dose of levodopa; the largest group of patients to benefit from bromocriptine entered the study because of excessive dyskinesia or "on-off" phenomena induced by levodopa. In 40 patients bromocriptine was stopped because of adverse reactions, absence of therapeutic response, or non-compliance with the protocol. The main problems were psychiatric disturbance (8 patients) and erythromelalgia (7 patients); these effects tended to occur late (mean 6 months and 10 months, respectively) and with high dosage (mean 66 mg and 115 mg daily). Other frequent adverse effects were dizziness and nausea; these began considerably earlier (at 2 months and 1 month) and with much lower dosage (31 mg and 12 mg daily). 4 patients died, for reasons apparently unrelated to therapy.

Bromocriptine↗
PubMed1999

Adverse cutaneous reactions to ticlopidine in patients with coronary stents.

A prospective study was carried out to assess the occurrence and character of adverse cutaneous reactions in patients receiving ticlopidine hydrochloride to prevent subacute thrombosis after having undergone placement of coronary stents. During a 1-year period such patients were requested to report any adverse cutaneous reactions, and those with skin reactions were referred for dermatological evaluation. Among the 136 patients who underwent stent placement by one of the authors, 20 were referred for dermatological evaluation. Of these, 16 (11.8%) fit the case definition of ticlopidine-associated cutaneous reactions. In the first 8 consecutive patients ticlopidine was withdrawn (in 2 of these a rechallenge test was later performed); in the next 8 patients ticlopidine was not discontinued before completion of the intended 4-week period of treatment. Patients remained under weekly follow-up and underwent a weekly blood count. Skin biopsies were obtained in 5 patients with different types of eruptions. The skin reactions appeared from 2 to 21 days after commencement of ticlopidine (mean, 10 days), lasting from 2 to 30 days (mean, 5 days). Only 3 patients had other adverse effects: neutropenia in 1 and abdominal pain and nausea in 2. The most common presentations were urticaria, pruritus, and maculopapular eruption. In 3 patients there were previously unreported reactions: fixed drug eruption, erythromelalgia-like eruption, and erythema multiforme-like eruption. Of note was the rapid clearing of the skin eruption in most cases even when the drug was not withdrawn. It was concluded that adverse cutaneous reactions are relatively common in association with ticlopidine treatment but that serious reactions are rare and the disappearance of the signs and symptoms is rapid, suggesting that discontinuation of the drug is not usually imperative.

Aged↗
PubMed2005

[When should a myeloproliferative syndrome be suggested in vascular medicine?].

Thrombotic events are frequent in polycythemia vera (PV) and in essential thrombocythemia (ET). The frequency of thrombotic complications at presentation of PV and ET is nearly 50%. The spectrum of thrombotic complications is broad: thrombosis of arteries, veins and microvessels have been reported. Venous thrombosis can involve all territories but PV and TE are the commonest underlying etiology for Budd-Chiari Syndrome and splanchnic veins thrombosis. Endogenous erythroid-colony formation may be seen in up to 78% of patients thought to have Budd Chiari Syndrome and in 48% of splanchnic veins thrombosis. Major arterial thrombotic complications occur in 20%, especially in the extremities and in cerebral circulation. Microcirculatory disturbances are common in ET, occurring in 29% at presentation and 27% during follow up. In the extremities, erythromelalgia, a characteristic syndrome of red and congested extremities with raised temperature and painful burning sensations, is noticed in 30 to 50% of TE. Other microcirculatory manifestations like acrocyanosis, blue toes, digital gangrene can occur. All of these manifestations are highly sensitive to aspirin. Cerebral microcirculatory symptoms occur in about one-third of patients: migraine, transient visual symptoms like scotomata, blurred vision are characterized by a sudden onset, a short duration and a sequential course. Three kinds of leg ulcers have been described: leg ulceration as a consequence of microcirculatory thrombosis, exceptionally, pyoderma gangrenosum, and leg ulcers attributed to side effects of hydroxyurea. Microcirculatory leg ulcers are the most common: they are painful, inflammatory and sometimes, necrotic. They heal with treatment of SMP. Hydroxyurea-induced leg ulcers are painful, fibrous and multiple in 60%. Cessation of hydroxyurea typically leads to wound healing. The Polycythemia Vera Study Group (PVSG) established diagnostic criteria for PV and TE. Because SMP can have incompletely expressed disease, other authors have proposed determination of serum erythropoietin, examination of bone marrow histology, and spontaneous endogenous colony assays for diagnosis of PV or TE. The individual thrombotic risk depends on elevated hematocrit for PV, age (> 60) and prior thrombosis for PV and TE. Congenital and acquired (antiphospholipid syndrome) thrombotic states probably increase the risk of thrombosis.

Humans↗
PubMed1996

Thrombotic and hemorrhagic complications in chronic myeloproliferative disorders.

Bleeding and thrombosis are major causes of morbidity and mortality in patients with chronic myeloproliferative disorders. We retrospectively evaluated 101 consecutive patients affected by primary thrombocytosis (46 male, 55 female, aged 18-84 years; mean +/- SD 61 +/- 15) followed for a period ranging from 6 months up to 10 years (median 5 years) at our hematological unit. At the time of diagnosis 48 patients were asymptomatic; 26 had clinical evidence of atherothrombosis (cerebral ischemic attacks, ischemic heart disease, peripheral occlusive arterial disease), ten had venous thrombosis, four experienced major hemorrhages, 23 presented microvascular ischemic manifestations namely erythromelalgia, paresthesias, acrocyanosis and dizziness. At presentation 51.2% of the patients had elevated serum lactic dehydrogenase, 34.5% hyperuricemia, and 23.4% serum creatinine > 1.2 mg/dL. Color Doppler ultrasound provided evidence of vascular stenosis or medium-intimal hyperplasia of epiaortic vessels in 48.9% of patients studied, and similar alterations of lower limb arteries in 23.8% of cases. Therapy modality included an antiplatelet agent (picotamide 300 mg/bid); a cytoreductive agent (busulphan, hydroxyurea, pipobroman or melphalan) was used when platelet count was > 800000/microL. Symptoms due to microvascular ischemia promptly regressed after picotamide and cytoreductive therapy. During follow-up. nine patients suffered from atherothrombotic events (transient ischemic attacks, ischemic stroke, unstable angina pectoris) and five developed deep vein thrombosis or superficial thrombophlebitis. Five patients experienced major hemorrhages (two melena, two hematuria, one perioperative bleeding); the two gastrointestinal hemorrhages occurred in patients self-medicated with non steroidal anti-inflammatory drugs, and the two episodes of hematuria occurred on oral anticoagulant therapy and aspirin respectively. No major bleeding occurred in patients on continuative therapy with picotamide, even in the presence of upper digestive tract disorders. Seven patients died: mortality resulted from one sudden coronary death, three solid neoplasia, one blast crisis, one anile, and one massive hemorrhage due to abdominal aortic prosthesis tearing. Our study suggests that a long-term antithrombotic prophylaxis with picotamide may be of benefit in patients affected by primary thrombocytosis; a controlled clinical trial is warranted to assess whether picotamide can ameliorate the natural history of the disease.

Adolescent↗
PubMed1997

Megakaryocytes and platelets in myeloproliferative disorders.

Increased megakaryocyte (MK) proliferation in bone marrow is a feature common to the three Ph-negative myeloproliferative disorders (MPDs), i.e. essential thrombocythaemia (ET), polycythaemia vera (PV), and myelofibrosis with splenic myeloid metaplasia (MMM), and to chronic myelocytic leukaemia (CML). Enlarged MKs with multilobulated nuclei and cell clustering in close proximity are the hallmark of all the Ph negative MPDs. Clonality of haematopoietic cells, based on X chromosome inactivation, can now be studied in a majority of female patients in all nucleated cell fractions as well as in platelets. Cytofluorometric studies have demonstrated a shift towards higher ploidy classes in PV and ET MKs which may be useful in discriminating between both primary and reactive thrombocytosis and CML patients which show a significant shift to lower MK ploidy values. The role of MK proliferation on the evolution of myelofibrosis common to MPDs has been firmly established. Implication of platelet-derived growth factor (PDGF) in myelofibrosis has already been demonstrated. More recently transforming growth factor beta (TGF beta) synthesized and secreted by MK has been implicated in fibroblasts stimulation. A significant increase in circulating colony-forming units of MKs (CFU-MK) has been repeatedly observed in MPDs as well as a spontaneous MK colony formation in a majority of ET patients. Hypersensitivity to thrombopoietin (TPO) in relation to a functional defect of the TPO-MPL pathway may play a major role in spontaneous MK growth. There is no currently available test of platelet functions able to predict the risk of occurrence of thrombotic or haemorrhagic complications in MPD patients. However, the role of platelet activation in the pathogenesis of ischaemic erythromelalgia has been established and a correlation between presenting haemorrhagic manifestations and platelet counts in excess of 1000 x 10(9)/l has been found.

Blood Platelets↗
PubMed2003

Biofeedback, cognitive-behavioral methods, and hypnosis in dermatology: is it all in your mind?

Biofeedback can improve cutaneous problems that have an autonomic nervous system component. Examples include biofeedback of galvanic skin resistance (GSR) for hyperhidrosis and biofeedback of skin temperature for Raynaud's disease. Hypnosis may enhance the effects obtained by biofeedback. Cognitive-behavioral methods may resolve dysfunctional thought patterns (cognitive) or actions (behavioral) that damage the skin or interfere with dermatologic therapy. Responsive diseases include acne excoriée, atopic dermatitis, factitious cheilitis, hyperhidrosis, lichen simplex chronicus, needle phobia, neurodermatitis, onychotillomania, prurigo nodularis, trichotillomania, and urticaria. Hypnosis can facilitate aversive therapy and enhance desensitization and other cognitive-behavioral methods. Hypnosis may improve or resolve numerous dermatoses. Examples include acne excoriée, alopecia areata, atopic dermatitis, congenital ichthyosiform erythroderma, dyshidrotic dermatitis, erythromelalgia, furuncles, glossodynia, herpes simplex, hyperhidrosis, ichthyosis vulgaris, lichen planus, neurodermatitis, nummular dermatitis, postherpetic neuralgia, pruritus, psoriasis, rosacea, trichotillomania, urticaria, verruca vulgaris, and vitiligo. Hypnosis can also reduce the anxiety and pain associated with dermatologic procedures.

Biofeedback, Psychology↗
PubMed2000

Paraneoplastic rheumatic syndromes.

Malignant neoplasms are associated with a wide variety of paraneoplastic rheumatological syndromes. Among these, hypertrophic osteoarthropathy, carcinoma polyarthritis, dermatomyositis/polymyositis, and paraneoplastic vasculitis are the most frequently recognized. Other less known associations are based upon a smaller number of reported patients, and include fasciitis, panniculitis, erythema nodosum, Raynaud's syndrome, digital gangrene, erythromelalgia and lupus-like syndromes. Musculoskeletal manifestations of malignancy may coincide, follow or antedate the diagnosis of cancer, or herald its recurrence. The clinical course generally parallels that of the primary tumour, and treatment of the underlying malignancy often results in regression of the rheumatic disorder. Awareness that cancer can cause certain non-metastatic symptoms is important for early diagnosis and treatment of an occult neoplasm. Rheumatic manifestations suggesting a hidden cancer include: rapid onset of an unusual inflammatory arthritis clubbing or diffuse bone pains in a patient 50 years of age or older, chronic unexplained vasculitis, refractory fasciitis, Raynaud's syndrome unresponsive to vasodilator therapy, rapidly progressive digital gangrene or Lambert-Eaton myasthenic syndrome. Management consists of control of the underlying cancer and symptomatic treatment of the rheumatic syndrome with non-steroidal anti-inflammatory drugs or corticosteroids.

Humans↗
PubMed2002

Quality of life issues in patients with essential thrombocythemia and polycythemia vera.

Essential thrombocythemia and polycythemia vera are both chronic progressive myeloproliferative disorders of insidious onset. If the excessive production of red cells and/or platelets is controlled, patients with these disorders may have prolonged survival. However, the clinical course of these patients can be complicated by a variety of events, including thrombotic episodes, bleeding episodes, arthropathies, pruritus, weakness, weight loss, neurologic impairment, erythromelalgia, fever, abdominal pain, and the life-threatening consequences of progression to myelofibrosis and/or acute leukemia. Effective control of hematopoiesis by phlebotomy or a variety of therapeutic agents has resulted in a reduction or elimination of many of these clinical events, but has not altered the evolution to myelofibrosis or acute leukemia. Use of each of these therapeutic strategies is also associated with a range of adverse events. Monitoring overall survival or a reduction in the frequency of clinical events has previously served as a means of assessing the results of these therapeutic interventions. Quality-of-life instruments have not been applied in a systematic fashion to the evaluation of outcomes in patients with these chronic myeloproliferative disorders. Quality-of-life assessments evaluate not only the state of well-being of a patient that results from an assessment of the individual's ability to perform everyday activities, which are reflective of physical, psychological, and social well-being, but also patient satisfaction with the control of disease and/or treatment-related symptoms. Quality-of-life instruments have been used to assess the clinical course of patients suffering from a variety of disorders, ranging from cancer to renal failure to chronic fatigue syndrome. Information about quality-of-life outcomes can contribute to the evaluation of variations in dose and timing of administration of therapeutic agents. It is possible that the side effects of a particular therapy may outweigh the disease regression achieved with a particular therapy. In the future, quality-of-life instruments may prove useful in prospectively evaluating therapeutic end points in patients with essential thrombocythemia and polycythemia vera.

Humans↗
PubMed2006

Clinical and laboratory features, pathobiology of platelet-mediated thrombosis and bleeding complications, and the molecular etiology of essential thrombocythemia and polycythemia vera: therapeutic implications.

Microvascular disturbances in essential thrombocythemia (ET) and polycythemia vera (PV), including erythromelalgia, and atypical and typical transient cerebral, ocular, and coronary ischemic attacks, are caused by platelet-mediated transient and occlusive thrombosis in the end-arterial circulation. ET patients with microvascular disturbances have shortened platelet survival, increased beta-thromboglobulin (beta-TG), platelet factor 4 (PF4), and thrombomodulin (TM) levels, and increased urinary thromboxane B2 (TXB2) excretion, indicating platelet-mediated thrombotic processes. Inhibition of platelet cyclooxygenase-1 by aspirin is followed by relief of microvascular disturbances; correction of shortened platelet survival; correction of increased plasma beta-TG, PF4, and TM levels; and correction of increased TXB2 excretion to normal. In PV associated with thrombocythemia, increased hematocrit and whole blood viscosity aggravate the platelet-mediated microvascular syndrome of thrombocythemia to produce major arterial and venous thrombotic complications. Correction of hematocrit to normal by phlebotomy will reduce the major arterial and venous thrombotic complications, but fails to prevent the platelet-mediated microvascular circulation disturbances in PV patients because thrombocythemia persists. Complete relief and prevention of microvascular and major thrombosis in ET and PV patients, in addition to phlebotomy, are obtained by treatment with aspirin and not with coumarin. The discovery of JAK2 V617F gain of function mutation in patients with myeloproliferative disorders (MPDs) expands our insights into the molecular etiology and biological features of ET, PV, and chronic idiopathic myelofibrosis (CIMF). The current concept is that heterozygous JAK2 V617F mutation with increased kinase activity is enough for megakaryocyte proliferation and increased hypersensitive platelets with no or slightly increased erythropoiesis in ET and in early PV mimicking ET. Homozygous JAK2 mutation with pronounced kinase activity is associated with trilinear megakaryocyte, erythroid, and granulocytic myeloproliferation, myeloid metaplasia, and secondary myelofibrosis (MF), with the most frequent clinical picture of classical PV complicated by major thrombosis in addition to the platelet-mediated microvascular thrombotic syndrome of thrombocythemia. The positive predictive value of a JAK2 V617F polymerase chain reaction test for the diagnosis of MPDs is high (near to 100%), but only half of ET and MF (sensitivity 50%) and the majority of PV (sensitivity 85 to 97%) are JAK2 V617F positive. Bone marrow histopathology, when used in combination with specific markers such as serum erythropoietin, PRV-1, endogenous erythroid colony formation, peripheral blood parameters and red cell mass, has a high sensitivity and specificity (near 100%) to detect the early and overt stages of the MPDs and to differentiate between ET, PV, and CIMF in both JAK2 V617F-positive and -negative MPDs.

Blood Platelets↗
PubMed2006

Aspirin for the control of platelet activation and prevention of thrombosis in essential thrombocythemia and polycythemia vera: current insights and rationale for future studies.

Polycythemia vera and essential thrombocythemia are chronic myeloproliferative disorders characterized by a relatively benign clinical course that may be complicated by arterial and venous thromboses. A thrombotic diathesis often manifests at diagnosis or in the preclinical phase of the myeloproliferative disease. Peculiar microcirculatory disturbances such as erythromelalgia and visual and hearing symptoms also commonly occur in these patients, and are highly responsive to aspirin. In a placebo-controlled trial in relatively low-risk polycythemic subjects, low-dose aspirin recently was shown to reduce the incidence of both arterial and venous thrombosis with a limited increase of the hemorrhagic risk. Due to its favorable benefit/risk profile, low-dose aspirin should be prescribed to all patients with polycythemia vera who have no contraindication to this treatment. Future studies should assess primarily the efficacy and safety of aspirin in essential thrombocythemia, and test the possible use of more aggressive antithrombotic strategies in high-risk polycythemic patients.

Aspirin↗